Globally, wastewater and sludge treatment plays a fundamentally important role in control of anthropogenic carbon impacts. Unfortunately, most of the infrastructure we see today was designed in the late 19th (e.g. thickening, dewatering, primary treatment, anaerobic digestion; thermal drying; nutrient extraction; biosolids recycling as fertilizer) or early 20th centuries (e.g. activated sludge treatment) and therefore was not designed to be either carbon, or energy efficient.
In absence of demolishing entire wastewater treatment plants due to their inefficiency, it is necessary to adapt existing works to meet modern demands. One successful way of doing this with respect to biosolids treatment is the application of thermal hydrolysis to increase renewable energy generation and reduce biosolids quantity, therefore reducing downstream processing requirements.
This paper presents results of a detailed model which calculates the carbon impact of numerous processes, and highlights the important role which thermal hydrolysis plays with respect to reducing carbon impact.
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